Mutilating tendon or ligament injuries arising from trauma or disease often require surgical reconstruction or surgical grafts in order to restore function. While autologous sources of tendon and ligament graft material, i.e. tissues that are harvested from the tissue recipient, are sufficient for minor deficits, they are quickly exhausted in cases of extensive tendon or ligament loss (White 1960). Considering that the use of autograft material from non-contiguous donor sites leads to additional operative time and donor site morbidity (Zhang et al., 2003; Zhang et al., 2009), the use of suitable, readily available, effective and safe allografts becomes a desirable target. However, the use of allogeneic graft material in its native form can lead to pronounced immune responses from the host compromising graft integrity and, ultimately, causing graft rejection and/or failure of the reconstruction.
Musculoskeletal interfaces that connect dissimilar tissues such as hard tissue, e.g. bone, and soft tissues, e.g. tendon, ligament, muscle, cartilage, that are crucial in the efficient and smooth load transfer between those tissues to ensure an optimal range of motion and stability, are highly prone to injuries and such injuries are difficult to treat. Because of large differences in the elastic modulus (EM) between soft and hard tissues, reconstruction of the transition zone is difficult and it is believed that even with current surgical techniques, this transition zone is never truly reconstituted (Thomopoulos et al., 2010).
Since healing between tissues of similar elastic moduli results in a stronger interface than between tissues of disparate elastic moduli, it would be highly desirable to have suitable, readily available, effective and safe composite tissue grafts available for immediate use, particularly in cases of extensive tissue interface injuries. The present invention addresses this need.